The preferred embodiment of the integrated pressure management system includes at least two operational configurations. In a first configuration of the integrated pressure management system, a poppet is disengaged from a poppet seal so as to permit fluid flow via a gap between the poppet and the poppet seal. In a second configuration of the integrated pressure management system, the poppet is engaged with the poppet seal so as to close the gap and to prevent the fluid flow. Preferably, the poppet seal is retained with respect to a housing of the integrated pressure management system.
According to the preferred embodiment of the integrated pressure management system, the poppet seal would be retained in an aperture near a mouth of the housing, which is molded from plastic. Preferably, the plastic at the mouth is softened by heating, and then formed over the seal without overheating the seal.
Attempts to form-over the mouth using spin forming and orbital forming operations were not successful.
Referring to FIGS. 1A-1D, another attempt to form-over a mouth 20 included positioning a conventional die 10 above the mouth 20 of the aperture in which a seal 30 is seated (FIG. 1A). The die 10, which is heated, is lowered against a tip 22 with a relatively low force, and by heating begins to soften the tip 22 (FIG. 1B). When the tip 22 is sufficiently softened, the die 10 can be pressed with a relatively greater force toward the mouth 20 so as to form over the tip 22 (FIG. 1C). After forming over the tip 22, the die 10 is raised and the seal 30 is retained in the aperture 20 (FIG. 1D). However, approximately 50% of the attempts to use the conventional die 10 resulted in unsuccessful retentions of the seal 30 in the mouth 20.
The inventors discovered that the conventional die 10 was too sensitive to dimensional variations of the tip 22. In particular, the inventors discovered that the form-over section 12 of the conventional die 10 includes a steeply inclined portion 14 that must contact the tip 22 in order to successfully retain the seal 30. Referring to FIGS. 2A and 2B, if the tip 22 is oversized with respect to the form-over section 12, the radially outside portion of the tip 22 can form a burr and the radially inside portion of the tip 22 does not fully form-over. Referring to FIGS. 2C and 2D, if the tip 22 is undersized with respect to the form-over section 12, the tip 22 engages a less inclined portion 16 of the form-over section 12. Rather than the tip 22 being formed over, the tip 22 is only slightly flattened without the seal 30 being retained.
The shape of the housing according to the preferred embodiment of the integrated pressure management system makes it very difficult to get a perfectly round and precisely sized tip 22. Adjustments to a conventional die 10, e.g., adjusting the diameter of the form-over section 12, cannot resolve the problems that arise due to out of round parts having sections of the circumference that are oversize or undersize with respect to the form-over section 12 of the conventional die 10. Thus, the inventors have identified a need to provide an apparatus and method that compensate for dimensional variations in the tips 22 and that can substantially ensure proper form-overs, regardless of variations in the size or roundness of the tip 22.